1. Technical Field
The disclosure relates to a flexible radiation detector, and in particular relates to a structure of a phosphor layer thereof.
2. Description of the Related Art
In general, digital X-ray image detectors are classified into a direct conversion type and an indirect conversion type. In the detectors of the indirect conversion type, an X-ray is transferred to a visible light, and the visible light is transferred to a current by a photoelectrical conversion device (e.g. diode). The current is then processed by a switching device (e.g. TFT) to obtain an X-ray image. The detectors of the indirect conversion type can be flexible; however, a phosphor dispersed in a resin thereof easily results in scattering to reduce X-ray image resolution. In the detectors of the direct conversion type, an X-ray can be directly transferred to electrons and holes by a photoelectric conversion device composed of a thick amorphous selenium layer (>500 μm). As such, the hole current may vertically flow to a pixel electrode and a switching device to obtain an X-ray image of high resolution. Accordingly, the conventional X-ray image detectors of high resolution have low flexibility due to the overly thick photoelectric conversion device, and the flexible X-ray image detectors have a low resolution. A novel X-ray image detector simultaneously having high resolution, high sensitivity, and flexibility is called for.